(1) Field of the Invention
This invention relates to burning waste gas, and more particularly to ignitors for igniting the flare.
(2) Description of the Related Art
It has long been customary around the production of petroleum products and the refining of them to burn or to flare waste gases. These waste gases may occur because of their noxious properties or because of a production or processing emergency.
In an emergency situation it is desirable that the operating personnel not have the responsibility of igniting the flare and once the gases are put to the flare that they will be ignited with certainty. Therefore, the reliability of the ignitor is one of its most important attributes.
Originally the flare pipes were vertical and often referred to as stacks. However, many of the flare pipes are horizontal, which introduces additional problems. The problem with many flare ignitors is the wind blowing them out. Of course the wind normally moves horizontally; therefore, with the vertical stack, all that was necessary was to protect the ignitor. However, with a horizontal flare, the wind may be blowing down the flare pipe. The difficulty is that the flame is blown back upon the ignitor parts and will often destroy them. The fire problem is paticularly pointed out in the U.S. Pat. No. 2,661,798 to Clevenger et al. and Rodman et al. U.S. Pat. No. 2,537,091; which describe different steps which have been taken to protect the ignitor from the damage from fire. These steps have often resulted in a loss of reliability.
Another problem is present, particularly with flares which are used during the drilling of oil wells. In such cases, the product to be burned comes directly from the well. Because of production, often times, various liquids such as water, mud, and heavy petroleum products having low volatility and high viscosity will be emitted from the flare pipe before any gases or intermittently with the production of gases. These liquids which are either incombustible or not readily combustible will put out the flame if one is already burning at the flare pipe. In addition to this, the liquids may flow into the ignitor, filling the ignitor, thereby preventing the fuel/air mixture normally used in such an ignitor from flowing into the combustion chamber of the ignitor.
The ignitor is often supplemented by a supercharger pipe, which is a pipe that brings fuel to the flare independent of the ignitor pipe. Such a supercharger pipe is shown in U.S. Pat. No. 2,830,658 to Smith and U.S. Pat. No. 4,025,281 to Lapp.
Spark plugs are often used to ignite the fuel/air mixture within the pilot burner. This is shown in U.S. Pat. No. 2,537,091 to Rodman et al; or U.S. Pat. No. 2,460,016 to Kuhn.
Pulse generators for the spark plug are old. Instead of constantly supplying high voltage electricity to the spark plugs so that there was a continuous spark across the spark plug, it is provided a pulse source that can be adjusted for a pulse from one pulse every minute to one pulse every second. The pulse is about one second duration. This increases the reliability particularly when the pulse are sent to the plug about every 15 seconds. I.e., the electrical coils of the transformer producing the high voltage electricity are not continuously in use; and therefore, have the ability to cool and the insulation within the transformer is not to deteriorate from the excessive heat.